System and method for the pre-treatment of rubber-modified asphalt cement, and emulsions thereof

ABSTRACT

This invention encompasses asphalt cement emulsions, as well as methods for preparing a pre-treated rubber-modified asphalt cement emulsions and methods for coating industrial surfaces using asphalt cement emulsions.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. ProvisionalApplication No. 61/071,473, filed Apr. 30, 2008. The application, in itsentirety, is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to an asphalt cement emulsion, and morespecifically relates to a pre-treated rubber-modified asphalt cementemulsion.

BACKGROUND OF THE INVENTION

Several attempts have been made to produce rubber-modified asphaltemulsions having the highly desirable properties of stability andprolonged high-level resistance to water-, fuel-, and ultraviolet (UV)light-associated degradation.

Specifically, for example, U.S. Pat. No. 5,492,561 (Flanigan) and U.S.Pat. No. 5,583,168 (Flanigan) describe processes for liquefying tirerubber in a TRMACS process, by heating crumb rubber and asphalt totemperatures of approximately 500° F. U.S. Pat. No. 5,539,029 (Burress)describes a method for preparing an asphalt emulsion comprising mixingaggregate with an aqueous emulsion comprising water, asphalt, athickening agent, latex rubber, and rubber particles. U.S. Pat. No.7,087,665 (Sylvester), U.S. Pat. App. No. 2005/0131113, filed Feb. 7,2005 (Sylvester), and U.S. Pat. App. No. 2007/2049762, filed Jul. 10,2006 (Sylvester) describe methods for preparing asphalt emulsionscomprising mixing a rubber-modified asphalt cement with aqueoussolutions comprising an emulsifier.

Although several achievements have been made in producing asphaltemulsions having desirable properties, a need still remain for improvedrubber-modified asphalt cement emulsions that possess superior stabilityand shielding properties.

The present invention provides such an improved emulsion, as well asmethods for preparing and using such an emulsion.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a method for preparingan asphalt cement emulsion, comprising: preparing a pre-treatmentmixture comprising a rubber-modified asphalt cement; and contacting thepre-treatment mixture with water and clay.

In another aspect, the present invention relates to a method forpreparing an asphalt cement emulsion, comprising: preparing apre-treatment mixture consisting of a rubber-modified asphalt cement,one or more emulsifiers, and an optional anti-foam agent, polymer latex,sulfonic acid, and/or water; and contacting the pre-treatment mixturewith water.

In another aspect, the present invention relates to a method forpreparing an asphalt cement emulsion, comprising contacting apre-treated rubber-modified asphalt cement with water and clay.

In another aspect, the present invention relates to a method forpreparing an asphalt cement emulsion, comprising contacting arubber-modified asphalt cement with an emulsifier comprising a diaminecompound and water.

In another aspect, the present invention relates to a method forpre-treating a rubber-modified asphalt cement, comprising contacting arubber-modified asphalt cement with an emulsifier comprising a diaminecompound.

In another aspect, the present invention relates to an asphalt cementemulsion comprising: a pre-treatment mixture consisting of arubber-modified asphalt cement, one or more emulsifiers, and an optionalanti-foam agent, polymer latex, sulfonic acid, and/or water; and water.

In another aspect, the present invention relates to an asphalt cementemulsion comprising: a rubber-modified asphalt cement; water; and aclay.

In another aspect, the present invention relates to an asphalt cementemulsion comprising: a rubber-modified asphalt cement; an emulsifiercomprising a diamine compound; and water.

In another aspect, the present invention relates to areadily-emulsifiable rubber-modified asphalt cement composition,comprising: rubber; asphalt cement; and an emulsifier comprising adiamine compound.

In another aspect, the present invention relates to areadily-emulsifiable rubber-modified asphalt cement composition,prepared by contacting the rubber-modified asphalt cement with anemulsifier comprising a diamine compound.

Several embodiments of the invention, including the above aspects of theinvention, are described in further detail as follows. Generally, eachof these embodiments can be used in various and specific combinations,and with other aspects and embodiments unless otherwise stated herein.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description, and the accompanying drawings towhich it refers, are provided describing and illustrating certainexamples or specific embodiments of the invention only and not for thepurpose of exhaustively describing all possible embodiments and examplesof the invention. Thus, this detailed description does not in any waylimit the scope of the inventions claimed in this patent application orin any patent(s) issuing form this or any related application.

To facilitate the understanding of the subject matter disclosed herein,a number of terms, abbreviations or other shorthand as used herein aredefined below. Any term, abbreviation or shorthand not defined isunderstood to have the ordinary meaning used by a skilled artisancontemporaneous with the submission of this application.

The term “rubber-modified asphalt cement” (RMAC) is defined herein tomean any asphalt cement that contains rubber or to which rubber has beenadded, such as the rubber-modified asphalt cement that is commerciallyavailable as tire rubber modified asphalt cement (TRMAC) from WrightAsphalt Products Co. (Houston, Tex.).

The term “asphalt cement” is used herein to mean any suitablenaturally-occurring asphalt or asphalt cement, syntheticallymanufactured asphalt or asphalt cement, such as any asphalt that is aby-product of a petroleum refining process, blown asphalt, blendedasphalt, residual asphalt, aged asphalt, petroleum asphalt, straight-runasphalt, thermal asphalt, paving grade-asphalt, performance gradedasphalt cement, asphalt flux, bitumen, or the like. Suitable performancegraded asphalt cements include, for example, any asphalt cements havingthe following characteristics set forth in ASTM D6373-99, the contentsof which are incorporated herein by reference:

PG64-22 PG58-28 Asphalt Cement Asphalt Cement Average 7-day max <58 <64Pavement Design Temp, ° C. Min. Pavement Design Temp, ° C. >−28 >−22Original Binder Flash Point Temp., D 92; min ° C. 230 230 Viscosity,D4402: 135 135 max. 3Pa · s Test Temp., ° C. Dynamic Shear, P 246: 58 64G°/sinδ, min. 1.00 kPa 25 mm Plate, 1 mm Gap Test Temp. at 10 rad/s, °C. Rolling Thin Film Over (Test Method D 2872) Mass Loss, max. percent1.00 1.00 Dynamic Shear, P 246: 58 64 G°/sinδ, min. 2.20 kPa 25 mmPlate, 1 mm Gap Test Temp. at 10 rad/s, ° C. Pressure Aging VesselResidue (AASHTO PP1) PAV Aging Temperature, ° C. 100 100 Dynamic Shear,P 246: 19 25 G°/sinδ, min. 5000 kPa 8 mm Plate, 2 mm Gap Test Temp. at10 rad/s, ° C. Creep Stiffness, P 245: −18 −12 S, max 300 MPa, m-value;min. 0.300 Test Temp at 60 s, ° C. Direct Tension, P 252: −18 −12Failure Strain, min. 1.0% Test Temp. at 1.0 mm/min, ° C.

Suitable asphalt cements also include, for example, any asphalts havingthe following characteristics:

Asphalt cement AC-20 AC-5 flux ASTM # Orig. visc. at 140° F. 1725 568 40ASTM D2171 in poise Penetration at 77° F. 57 153 300+ ASTM D5 100 g. 5sec. dmm Softening point ° F. 118 104 65 ASTM D36 Flash point ° F. (COC)585 588 565  ASTM D92 Ductility at 39.2° F. 0 5.5 15 ASTM D113 5 cm/min.cm

The term “rubber” is used herein to mean any material made substantiallyof rubber, such as, for example, virgin rubber, recycled rubber (such asfrom tires, inner-tubes, gaskets, rubber scrap, or the like), peelrubber, cured rubber, and/or processed rubber of any polymer type(s),such as, for example, tire rubber (e.g., scrap tire rubber, whole tiresolid rubber, and/or scrap whole tire rubber), non-solvent-treatedrubber, non-pre-swelled rubber, and/or any rubber that comprises lessthan about 5% (such as less than about 3% or even 1%) of talc powder,such as wherein the rubber has no insoluble materials such as metals,fibers, cords, wood, rocks, dirt, and/or the like. The rubber can existin any form, such as in the form of particles, crumbs, and/or otherparticulate forms (e.g., shavings, fines, beads, or the like), which canbe produced and/or processed in any manner (such as via vulcanization,ambient grinding and/or cryogenic grinding). Moreover, the rubberparticles can be of any suitable size prior to formation of the RMAC,such that, for example, greater than about 90 wt. % (such as greaterthan about 95 wt. %, or even greater than about 99%) of the rubberparticles, relative to the total weight of the rubber particles, have asize of less than about 20 mesh (such as less than about 30 mesh, about40 mesh, about 50 mesh, about 60 mesh, or even less than about 70 mesh).

Preparation of Rubber-Modified Asphalt Cement

The rubber-modified asphalt cement (RMAC) can be prepared in anysuitable manner, such as by combining, mixing, contacting, and/orblending rubber with asphalt cement under heat (e.g., at a temperaturegreater than about 350° F., greater than about 400° F., or greater thanabout 450° F., such as a temperature of about 350-525° F., about400-500° F.), pressure and/or other conditions that are suitable tocause at least some (e.g., a substantial amount) of the rubber to beliquefied or otherwise subsumed, incorporated, and/or integrated intothe asphalt cement. For example, the RMAC can be prepared using anyprocess and/or method described in U.S. Pat. No. 5,492,561 (Flanigan),U.S. Pat. No. 5,583,168 (Flanigan), U.S. Pat. No. 5,496,400 (Doyle),U.S. Pat. No. 7,087,665 (Sylvester), U.S. Pat. App. No. 2005/0131113,filed Feb. 7, 2005 (Sylvester), and/or U.S. Pat. App. No. 2007/2049762,filed Jul. 10, 2006 (Sylvester), the contents of which are incorporatedherein in their entirety.

The RMAC is preferably prepared in such a manner that the rubber isincorporated into the asphalt cement without any significant and/orsubstantial degradation and/or destruction of the base asphalt cementmedium occurring. In one embodiment, for example, the rubber and asphaltcement are mixed without air blowing, oxidation, and/or or substantialdistillation of the asphalt cement component. The asphalt cement andrubber, in this regard, can be stored in any suitable manner prior tomixing.

In one embodiment, the asphalt cement is stored in a vessel at atemperature of about 350° F., and whole tire rubber granules beingstored in a separate vessel at ambient temperature. The asphalt cementmedium is then pumped from the storage vessel through a pump and heatexchanger, where it increases in temperature to about 400-500° F.,through a pipeline into a reactor vessel. If the temperature of theasphalt cement medium in the reactor vessel is substantially below 500°F., the asphalt cement medium may be recirculated through a pipeline,through a pump and heat exchanger, to raise the temperature to about500° F. before being returned to the reactor vessel. The reactor vesselpreferably has a top exit for removal of excess gaseous hydrocarbons andother gaseous vapors, such as H₂S, which are disposed of, for example,by incineration at a temperature of about 1350° F.

Whole tire rubber granules can be fed pneumatically from a storagevessel into the pipeline which carries the asphalt cement medium fromthe heat exchanger to the reactor vessel. The whole tire rubber granulesmix with and become wetted by the heated asphalt cement medium in thepipeline before being discharged into the reactor vessel. When dischargeof the complete batch of asphalt cement medium and whole tire rubberinto the reactor vessel is complete and a temperature of 500° F. isachieved, circulation of the mixture in the reactor vessel is started.The mixture of asphalt cement and whole tire rubber is circulated fromabout the middle of the reactor vessel, through a pipeline and pump(such as a 450-600 gallon/minute pump), back into the reactor vesselthrough nozzles (such as dual port jet spray nozzles), and into thebottom of the reactor vessel. Circulation is continued at 500° F. untilthe whole tire rubber is completely integrated into the asphalt cementmedium. In one embodiment, the temperature in the reactor vessel ismaintained by use of a fire tube burner in the reactor vessel whichmaintains the temperature of the mixture in the reactor vessel so thatcirculation through the heat exchanger is not needed during theincorporation process. The finished product is pumped through a pipelineinto a holding vessel before being blended, oxidized, polymer modified,or shipped as is.

In another embodiment, the asphalt cement and whole tire rubber arecirculated at least in part through a heat exchanger.

In one embodiment, the dual port jet spray nozzles are two fixed jettingnozzles which face away from each other at an angle of 180° and whichare each angled downwardly at 45° to promote mixing throughout themixture in the reactor vessel. In a non-limiting example, the nozzlesmay each be formed from a 6″ pipe in which the opening is tapered to a1.5 inch opening. Using such an arrangement, intimate mixing of thewhole tire rubber granules and the asphalt cement medium is achievedwhile simulating a boiling action in the liquid mixture in the reactorvessel. The jet spray nozzles provide a propulsion spray of the liquidmixture within the body of the liquid mixture in the reactor vesselwhich promotes turbulence, increases pressure and simulates a boilingaction in the liquid mixture. Other arrangements of nozzles whichachieve this effect may be used. While one embodiment includes twostationary nozzles, rotating nozzles or a different number orarrangement of nozzles may be used to achieve turbulence. The turbulencecreated allows the mixture to move upwardly through the reactor vessel.The incorporated product is lighter than the unincorporated or lessincorporated mixture and tends to rise through the reactor vessel. Thus,when the mixture is pulled from about the middle of the reactor vesselfor circulation through a pipeline and pump, the mixture circulatedtends to be less incorporated than the mixture at the top of the reactorvessel, and during recirculation of this less incorporated mixture, isrecirculated and the tire rubber granules are further softened in theturbulent environment and integrated into the asphalt cement mediumuntil the samples obtained show a completely incorporated product.

The pump which generates the liquid flow through the nozzles may, innon-limiting example, be a 400 gallon per minute pump. The effect of therecirculation is to provide suction of the mixture from the middleportion of the reactor vessel and discharge of the mixture into thebottom portion of the reactor vessel.

The RMAC can comprise any desired amount of rubber. For example, theRMAC can comprise greater than about 5 wt. %, such as greater than about8 wt. %, about 10 wt. %, about 12 wt. %, or even greater than about 14wt. % of rubber, relative to the total weight of the RMAC, and/or have arubber content in the range of about 5-15 wt. %, such as about 6-14 wt.%, about 7-13 wt. %, about 7.5-12.5 wt. %, about 8-12 wt. %, about8.5-12.5 wt. %, or even about 9-11 wt. %, relative to the total weightof the RMAC, as well comprise one or more (including all) of theproperties described in this section of the application (for example,rubber content, flash point, softening point, penetration, and/orsolubility). In another embodiment, the RMAC can be more concentrated,i.e., having one or more properties (for example, rubber content, flashpoint, softening point, penetration, and/or solubility) different and/orhigher than those desired for the subsequent pre-treatment and/oremulsification steps. For example, the RMAC can comprise greater thanabout 16 wt. %, about 18 wt. %, about 20 wt. %, about 25 wt. %, about 30wt. %, or even greater than about 35 wt. % of rubber (relative to thetotal weight of the RMAC), and/or have a rubber content in the range ofabout 16-35 wt. %, about 18-30 wt. %, about 20-35 wt. %, or about 20-30wt. %, relative to the total weight of the RMAC. In this regard, in theevent that the RMAC has one or more properties (for example, rubbercontent, flash point, softening point, penetration, and/or solubility)that are higher than the desired properties for the subsequentpre-treatment and/or emulsification steps, the RMAC can be modifiedprior to these subsequent steps, such as by blending the RMAC withasphalt. In one embodiment, for example, a RMAC concentrate havinggreater than about 30 wt. % of rubber, relative to the total weight ofthe RMAC, is blended (prior to the pre-treatment and emulsificationsteps) with additional asphalt in a manner such that the RMAC comprisesabout 5-15 wt. % of rubber, relative to the total weight of the RMAC, aswell as one or more (including all) of the properties described in thissection of the application (for example, rubber content, flash point,softening point, penetration, and/or solubility).

In one embodiment, the rubber within the RMAC has an average size ofless than about 20 microns, such as less than about 18 microns, about 16microns, about 14 microns, about 12 microns, about 11 microns, about 10microns, about 9 microns, about 8 microns, about 7 microns, about 6microns, about 5 microns, about 4 microns, about 3 microns, about 2microns, about 1 micron, about 0.75 micron, about 0.5 micron, or evenless than about 0.1 micron.

In another embodiment, greater than about 1% (such as greater than about3%, about 5%, about 10%, about 15%, or even greater than about 10% byweight) of the rubber in the RMAC has an average size of about 0.1-20(such as about 1-15, about 5-15, about 5-20, about 10-20, or even about10-15) microns, with the remainder of the rubber having an averageparticle size of less than about 10 (such as less than about 8, about 6,or even less than about 4) microns. In another embodiment, the RMACcomprises less than about 8 wt. % (such as less than about 6 wt. %, lessthan about 5 wt. %, less than about 4 wt. %, less than about 3 wt. %,less than about 2 wt. %, less than about 1 wt. %, less than about 0.5wt. %, less than about 0.25 wt. %, substantially no, or even no) rubberthat is in a solid state.

In one preferred embodiment, the RMAC exhibits a solubility intrichloroethylene (as determined via ASTM D2042) of at least about 90%(such as at least about 92%, at least about 94%, at least about 95%, atleast about 96%, at least about 97%, at least about 98%, or even atleast about 99%). For example, it is preferred, in one embodiment, thatwhen about 3 grams of the RMAC is dissolved in about 100 mL oftrichloroethylene and filtered through a 150 mm No. 52 filter paper,less than about 10 wt. % (such as less than about 8 wt. %, about 6 wt.%, about 5 wt. %, about 4 wt. %, about 3 wt. %, about 2 wt. %, or evenless than about 1 wt. %) of the RMAC remains on the filter paperfollowing such filtering. Preferably, the RMAC also exhibits a softeningpoint (as determined via ASTM D36) greater than about 90° F., such asgreater than about 100° F., or even greater than about 110° F.—a pointat which, for example, a weight (such as a steel ball having a diameterof about 9.5 mm and a mass of about 3.50±0.05 g) penetrates or settlesat least about 1 inch into a sample of the RMAC, using a ring and ballsoftening point apparatus. In one preferred embodiment, the RMAC has asoftening point of about 115-125° F.

Alternatively, or in addition, the RMAC comprises a penetration at 77°F. (as determined via ASTM D5) of less than about 60 dmm, such as lessthan about 50 dmm, about 40 dmm, about 30 dmm, about 20 dmm, or evenless than about 10 dmm (such as about 5-50 dmm, about 10-40 dmm, about15-35 dmm, or even about 15-30 dmm), at which, for example, a 1mm-diameter needle penetrates into the RMAC at a needle load of about100 grams for a duration of about 5 seconds. Alternatively, or inaddition, the RMAC comprises a flash point (as determined via ASTM D 93)of at least about 460° F., such as at least about 480° F., at leastabout 500° F., at least about 510° F., at least about 520° F., at leastabout 530° F., at least about 540° F., or even at least about 550° F.

In one embodiment, the RMAC is an asphalt cement concentrate having thefollowing properties:

Content Derived from Recycled Tire Rubber = 18-25% Solubility inTrichloroethylene (ASTM D2042) = 97.5% (min) Penetration @ 25° C. (ASTMD 5) = 60-90 dmm Absolute Viscosity @ 60° C. (ASTM D2171) = 1000-1600Flash Point - Cleveland Open Cup (ASTM D 92) = 450 F (min) SofteningPoint (ASTM D36) = 110-120 F

In one embodiment, the RMAC comprises about 9-13 wt. % of rubber(relative to the total weight of the RMAC), a penetration at 77° F. (asdetermined via American Society for Testing and Materials (ASTM) D5) ofabout 18-22 dmm, a softening point (as determined via ASTM D36) greaterthan about 112° F., and a solubility in trichloroethylene (as determinedvia ASTM D2042) of at least about 98%.

In some embodiments, in addition to the rubber and asphalt cementcomponents, other additives that enhance, cause, and/or assist indevulcanization, liquefaction, and/or break-down of the rubber arecombined, mixed, contacted, and/or blended with the rubber and/orasphalt cement components prior to and/or during contact of the rubberand asphalt cement in preparing the RMAC. For example, such otheradditives can aid in incorporation and/or combination of the rubber intothe asphalt cement, and/or to adjust or alter the physical properties(e.g., softening point, hardness, stability) of the RMAC. For example,any anti-foam agents, polymer latex, and/or sulfonic acids (e.g., DBSAand/or p-TSA) can be used in preparing the RMAC, such as described inU.S. Pat. No. 5,496,400 (Doyle), U.S. Pat. No. 7,087,665 (Sylvester),U.S. Pat. App. No. 2005/0131113, filed Feb. 7, 2005 (Sylvester), and/orU.S. Pat. App. No. 2007/2049762, filed Jul. 10, 2006 (Sylvester). Insome preferred embodiments, however, no such other additives are used inpreparing the RMAC.

Pre-Treatment of RMAC

Following preparation of the RMAC, and before emulsification of the RMACwithin an aqueous solution, the RMAC is preferably pre-treated with oneor more emulsifiers in a chemical pre-treatment and/or modificationstep. Any suitable amount of one or more emulsifiers can be combined,mixed, contacted, and/or blended with the RMAC. In one embodiment, about0.1-10 wt. % (such as about 0.5-8 wt. %, or even about 1-5 wt. %) ofemulsifier is combined, mixed, contacted, and/or blended with 90-99.9wt. % (such as about 92-99.5 wt. %, or even about 95-99 wt. %) of RMAC,relative to the total weight of the pre-treated RMAC.

The emulsifier can be any suitable emulsifier that increases the easewith which the RMAC forms an emulsion in a subsequent emulsificationstep, such as in an emulsification solution (such as an aqueousemulsification solution, for example in the form of a water and claysolution or slurry that lacks any emulsifiers) and/or decreases thetackiness and/or enhances other desired properties of such an emulsifiedRMAC product. In one embodiment, for example, the emulsifier comprisesat least about 20 wt. % (such as at least about 20 wt. %, about 30 wt.%, about 40 wt. %, about 50 wt. %, about 60 wt. %, about 70 wt. %, about80 wt. %, or even at least about 90 wt. %) of an amine compound, such asa diamine compound, or any compound having two or more amine groups(such as a compound having two or more amine groups that is highlysalted and/or any other desirable or effective diamine (such as simplediamine) that is highly salted, and optionally one or more of a furtheramine compound (e.g., a monoamine compound, such as an amine oxyalkylatecompound), one or more aromatic hydrocarbon compounds, a carboxylic acidcompound, and/or a tall oil compound or derivative. In one preferredembodiment, the emulsifier comprises about 20-60 wt. % of the diaminecompound and about 10-50 wt. % of the further amine compound. In anotherpreferred embodiment, the emulsifier comprises (i) about 30-50 wt. % ofa diamine compound; (ii) about 20-40 wt. % of an amine oxyalkylatecompound; (iii) about 15-25 wt. % of a carboxylic acid compound; (iv)about 5-10 wt. % of one or more aromatic hydrocarbon compounds; and (v)about 5-10 wt. % of a tall oil compound. In another preferredembodiment, the emulsifier is CORSAPAVE 5159™, available from CorsicanaTechnologies (Corsicana, Tex.).

Any suitable method can be used for combining, mixing, contacting,and/or blending the one or more emulsifiers with RMAC. In oneembodiment, the emulsifier(s) is combined with the RMAC at a temperatureof about 300-400° F. (such as about 325-375° F., or even about 325-350°F.). Any suitable mechanical means can be used to combine, mix, contact,and/or blend the emulsifier(s) with the RMAC, such as, for example, areactor vessel or simple mixer. In one embodiment, for example, theemulsifier(s) is combined with the RMAC in a mixer at a temperature ofabout 300-400° F. (such as about 325-375° F., or 325-350° F.) until adesired level of combining, mixing, contacting, and/or blending isachieved. In another embodiment, the blending or mixing process isachieved through use of a pump or tank circulation system, such as asystem having a blade mixer or air- or nitrogen-based tank agitationvessel. In another embodiment, blending is accomplished through use ofan in-line blender that comprises a circulation line, an injection linefor feeding the chemical, and a static in-line mixer.

In one embodiment, the pre-treated RMAC comprises a softening point thatis lower than the softening point of the RMAC prior to pretreatment. Inthis manner, pre-treatment of the RMAC allows for the preparation of anenhanced (such as readily-emulsifiable, readily-stored, and/or highand/or enhanced stability) RMAC, as compared to RMAC that is notpre-treated; an enhanced RMAC emulsion, as compared to an emulsion ofRMAC that is not pre-treated; and/or ultimately an enhanced curedcoating formed by an RMAC emulsion that is curable (such as a curedcoating having a reduced and/or low softening point), as compared to acured coating formed by a conventional RMAC emulsion. In one embodiment,for example, pre-treatment of the RMAC decreases and/or reduces thesoftening point of the RMAC by at least 0.5%, such as by at least about1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about8%, about 9%, or even by at least about 10%, as compared to a RMAC thatis not pre-treated. In another preferred embodiment, the pre-treatedRMAC comprises a softening point of about 110-120° F. Alternatively, orin addition, the pre-treated RMAC can be stably stored (such as withoutany significant or substantial degradation and/or settling) at atemperature of less than about 400° F. (such as less than about 375° F.,about 350° F., about 325° F., about 300° F., about 275° F., about 250°F., about 225° F., about 200° F., or even less than about 150° F., suchas at a temperature of about 200-400° F., or about 300-375° F., or even325-350° F.) for a duration of greater than 6 hours (such as greaterthan about 12 hours, about 18 hours, about 1 day, about 2 days, about 3days, about 5 days, about 1 week, about 2 weeks, about 3 weeks, about 1month, about 2 months, or even about 3 months).

In some embodiments, in addition to the emulsifier(s) used in thepre-treatment process and the RMAC, the pre-treatment mixture furthercomprises one or more optional additives, such as, for example, one ormore anti-foam agents, one or more thickeners, polymer latex, and/orwater. In other embodiments, the pre-treatment mixture of RMAC andemulsifier(s) does not contain any other additives (such as water).

Preparation of Emulsification Solution

The emulsification solution (with which the pre-treated RMAC forms apre-treated RMAC emulsion) can be any suitable aqueous solutioncomprising water and optionally a clay. In one preferred embodiment, forexample, the emulsification solution comprises water and a clay (such assepiolite clay or sea mud). In another embodiment, the emulsificationsolution comprises water, clay, and no other additives or components.

The emulsification solution can comprise any suitable clay, such as anypartially hydrophobic clay, any substantially hydrophobic clay, and/orany fully hydrophobic clay. Alternatively, or in addition, theemulsification solution can comprise any clay that comprisesnon-spherical, irregularly-shaped, and/or elongated particles. In onepreferred embodiment, for example, the clay is a clay that is stableand/or resistant to breakdown when contacted with water and/or does notswell and/or undergo shape change when contacted with water. Moreover,the clay can be any fibrous clay (such as a fibrous clay mineral ofpalygorskite type), non-bentonite clay, and/or any clay having a Loss onIgnition (LOI) at 100° C. of about 10-20 (such as about 12-18, or evenabout 14-17); a boiling point greater than about 800° F. (preferably,greater than about 900° F., or even greater than about 1000° F.); and/ora specific gravity of about 1.0-3.5. Alternatively, or in addition, theclay can comprise one or more of: less than about 70 wt. % of silicon(such as less than about 68 wt. %, about 66 wt. %, about 64 wt. %, about62 wt. %, about 60 wt. %, about 58 wt. %, or even less than about 56 wt.%); less than about 10 wt. % of aluminum (such as less than about 8 wt.%, about 7 wt. %, about 6 wt. %, or even less than about 5 wt. %);greater than about 10 wt. % of magnesium (such as greater than about 12wt. %, about 14 wt. %, about 16 wt. %, or even greater than about 18 wt.%); less than about 3 wt. % of iron (such as less than about 2.5 wt. %,about 2.0 wt. %, or even less than about 1.5 wt. %); about 0.1-3 wt. %of calcium (such as about 0.25-2.0 wt. %, about 0.25-1.0 wt. %, or evenless than about 3 wt. %, less than about 2 wt. %, or even less thanabout 1 wt. %); less than about 5 wt. % of sodium (such as less thanabout 4 wt. %, less than about 3 wt. %, less than about 2.5 wt. %, lessthan about 2 wt. %, or even less than about 1.5 wt. %); and/or about0.1-5 wt. % of potassium (such as about 0.5-4.0 wt. %, about 0.5-3.0 wt.%, about 0.5-2.0 wt. %, or even less than about 5 wt. %, less than about4 wt. %, less than about 3 wt. %, less than about 2 wt. %, or even lessthan about 1.5 wt. %). In one preferred embodiment, the emulsificationsolution comprises a clay that comprises: (i) about 0.1-60 wt. % ofsilicon; (ii) about 0.1-10.0 wt. % of aluminum; (iii) greater than about10 wt. % of magnesium; (iv) about 0.1-3.0 wt. % of iron; (v) about0.1-3.0 wt. % of calcium; and (vi) less than about 2 wt. % of sodium;and (vii) less than about 5 wt. % of potassium. In another preferredembodiment, the emulsification solution comprises sepiolite clay or seamud. In yet another preferred embodiment, the emulsification solution isan aqueous solution or slurry (such as a blended slurry or single-phaseslurry) comprising softened water at 120-140° F. and a clay compound(such as a sepiolite clay compound).

Any suitable concentration of clay can be added to the emulsificationsolution, such that, for example, when the emulsification solution iscombined, mixed, contacted, and/or blended with the pre-treated RMAC toform a pre-treated RMAC emulsion, the emulsion comprises a clayconcentration of less than about 10 wt. %, such as less than about 9 wt.%, about 8 wt. %, about 7 wt. %, about 6 wt. %, about 5 wt. %, about 4wt. %, about 3 wt. %, about 2 wt. %, or even less than about 1 wt. %(such as, for example, about 0.1-10 wt. %, about 0.5-8 wt. %, about 1-7wt. %, about 1-6 wt. %, about 1-5 wt. %, or even about 1-4 wt. %),relative to the total weight of the pre-treated RMAC emulsion. Any ofthe clay-containing emulsification solutions can be prepared in anysuitable manner, such as by combining, mixing, contacting, and/orblending water and clay at a temperature of about 80-180° F., such asabout 90-150° F., about 100-140° F., or even about 110-130° F.

In some embodiments, in addition to water and clay, the emulsificationsolution comprises any suitable other additives, such as otherthickeners, polymer latex, surfactants, and/or anti-foam agents.

In some embodiments, for example, in addition to water and clay, theemulsification solution comprises any suitable other thickener(s),including but not limited to associative thickeners, polyurethanes,nonionic surfactants, alkali swellable latex thickeners, cellulose,cellulose derivatives, modified cellulose products, plant and vegetablegums, starches, alkyl amines, polyacrylic resins, carboxyvinyl resins,polyethylene maleicanhydrides, polysaccharides, acryliccopolymers,hydrated lime (such as cationic and/or nonionic lime), and/or any otherthickener known in the art.

In some embodiments, for example, in addition to water and clay, theemulsification solution further comprises polymer latex. Polymer latexmay be included, in some embodiments, to enhance adhesion, waterresistance, and/or other desired physical properties of the pre-treatedRMAC emulsion. Such polymer latex can comprise a rubber or elastomericlatex in which globules of rubber or elastomer are suspended in anaqueous medium, such as, for example, styrene-butadiene rubber latex(“SBR latex”), neoprene and/or natural rubber, acrylics, vinylacrylics,acrylic terpolymers, nitrite, polyvinyl alcohol, polyvinyl acetate,vinyl acetate-ethylene, vinyl ester copolymers, ethylene vinyl chloride,polyvinylidene chloride, butyl rubber, acrylonitrile-butadiene,polyurethanes, silicones, block copolymers such as styrene-isoprene(SIS), styrene-ethylene-vinyl acetate (SEVAS), styrene acrylate, andcombinations and mixtures thereof.

In some embodiments, for example, in addition to water and clay, theemulsification solution further comprises one or more surfactants, suchas, for example, any non-ionic, cationic, and/or anionic surfactant,such as any surfactant that includes dodecyl benzenesulfonic acid, anynon-ionic surfactant that includes ethylhexanol, or any combination ormixture thereof.

In some embodiments, for example, in addition to water and clay, theemulsification solution further comprise an anti-foam agent, such as,for example, Dow Anti-Foam 1400® (available from Dow Chemical Company,Midland, Mich.), Dow Anti-Foam Component A® (available from Dow ChemicalCompany, Midland, Mich.), Surfynol 104A® (available from Air ProductsCorporation) may be added to the emulsification solution or may be postadded to the pre-treated RMAC emulsion. The emulsification solution, inthis regard, can comprise any suitable concentration of one or moreanti-foam agents, such as, for example, about 0.0025-0.05 wt. % of ananti-foam agent.

Emulsion of Pre-Treated RMAC

The pre-treated RMAC can be emulsified in any suitable manner bycombining, mixing, contacting, and/or blending any desired amount of thepre-treated RMAC with any corresponding amount of the emulsificationsolution, to produce a pre-treated RMAC emulsion having any desiredproperties. In one preferred embodiment, the pre-treated RMAC emulsionis prepared such that it comprises less than about 55 wt. %, such asless than about 50 wt. %, about 48 wt. %, about 45 wt. %, about 35 wt.%, about 30 wt. %, about 25 wt. %, about 20 wt. %, about 15 wt. %, oreven less than about 10 wt. %, such as about 10-55 wt. %, about 10-50wt. %, about 10-48 wt. %, about 10-45 wt. %, about 10-40 wt. % about15-40 wt. %, about 20-40 wt. %, about 25-40 wt. %, about 15-35 wt. %,about 20-35 wt. %, about 10-30 wt. %, about 15-30 wt. %, or even about20-30 wt. %) of solids (pre-treated RMAC and clay), relative to thetotal weight of the pre-treated RMAC emulsion. Alternatively, or inaddition, the pre-treated RMAC emulsion comprises about 0.01-25 wt. %(such as about 0.1-20 wt. %, about 0.1-15 wt. %, about 0.1-10 wt. %,about 0.1-8 wt. %, about 0.1-6 wt. %, about 0.14 wt. %, about 0.5-3 wt.%, about 0.5-2 wt. %, or even less than about 20 wt. %, less than about15 wt. %, less than about 10 wt. %, less than about 5 wt. %, less thanabout 4 wt. %, less than about 3 wt. %, less than about 2 wt. %, or evenless than about 1 wt. %) of rubber, relative to the total weight of thepre-treated RMAC emulsion. Alternatively, or in addition, thepre-treated RMAC emulsion comprises about less than about 6 wt. %, about4 wt. %, about 2 wt. %, such as less than about 1.5 wt. %, about 1.0 wt.%, about 0.8 wt. %, about 0.6 wt. %, about 0.4 wt. %, about 0.2 wt. %,or even less than about 0.1 wt. % (such as about 0.01-1.0 wt. %, about0.1-1.0 wt. %, or even about 0.1-0.8 wt. %) of the pre-treatmentemulsifier, relative to the total weight of the pre-treated RMACemulsion.

The pre-treated RMAC emulsion can have any suitable viscosity. In someembodiments, the emulsion has a viscosity of about 20-80 Krebs Units(KU), such as about 25-75 KU, about 30-70 KU, or even about 35-65 KU,such as a converted viscosity from the Kreb Unit tester of about 50-500cP, about 75-450 cP, or even about 100-400 cP. In other embodiments,when a high concentration emulsion (such as having a high concentrationof RMAC) is desired, the emulsion can have a viscosity of about 25-200KU, about 25-190 KU, about 30-180 KU, about 35-170, or even about 40-160KU. In some embodiments, the pre-treated RMAC emulsion has a viscositythat is at least partially temperature insensitive and/orviscosity-stabilized. In some embodiments, for example, the emulsion canhave no appreciable change in viscosity (such as less than about a 20%,about 15%, about 10%, about 5, or even less than about a 1% change inviscosity) in the temperature ranges of about 60-100° F., about 60-120°F., about 60-140° F., or even about 40-140° F., unlike conventional RMACemulsions which may require on-site heating in order to achieve desiredviscosity.

Alternatively, or in addition, the pre-treated RMAC emulsion comprises aspecific gravity (as determined via ASTM D 2939.07) less than about 2.0,such as less than about 1.5, about 1.4, about 1.3, about 1.2, about 1.1,about 1.0, about 0.8, or even less than about 0.6. Alternatively, or inaddition, less than about 1 wt. % (such as less than about 0.8 wt. %,about 0.6 wt. %, about 0.4 wt. %, about 0.2 wt. %, about 0.1 wt. %,about 0.05 wt. %, or even less than about 0.01 wt. %) of the pre-treatedRMAC emulsion, relative to the total weight of the pre-treated RMACemulsion, remains on a 850-um mesh sieve following contact of the sievewith the pre-treated RMAC emulsion during the Sieve Emulsion Test inaccordance with ASTM D 6933-04, such as when contacting the emulsion andsieve at an emulsion temperature of about room temperature.Alternatively, or in addition, greater than about 20 wt. % (such asgreater than about 25 wt. %, about 30 wt. %, about 35 wt. %, or evengreater than about 48 wt. %) of the pre-treated RMAC emulsion remainsafter heating the emulsion during the Residue By Evaporation Test inaccordance with ASTM D 2939.08, such as to a temperature of about 221±4°F. for a duration until successive hourly weighing shows loss of 0.05 orless of the emulsion (such as for about 4 hours). Alternatively, or inaddition, less than about 80 wt. % (such as less than about 75 wt. %,about 70 wt. %, about 65 wt. %, or even less than about 52 wt. %) lossof the emulsion occurs when the emulsion is heated during the Residue ByEvaporation Test, such as to a temperature of about 221±4° F. for aduration until successive hourly weighing shows loss of 0.05 or less ofthe emulsion (such as for about 4 hours).

The pre-treated RMAC can be emulsified in any suitable manner bycombining, mixing, contacting, and/or blending the pre-treated RMAC withthe emulsification solution. In one preferred embodiment, thepre-treated RMAC is heated and/or maintained at a temperature of about310-375° F. (such as about 310-350° F.), and is combined, mixed,contacted, and/or blended with an emulsification solution that has beenheated and/or maintained at a temperature of about 70-130° F., such asabout 75-125° F., about 80-120° F., about 85-115° F., or even about90-110. Any suitable method can be employed for combining, mixing,contacting, and/or blending the pre-treated RMAC and emulsificationsolution, such as, for example, milling. In one preferred embodiment,the pre-treated RMAC and emulsification solution are combined in such amanner that at least a portion (e.g., substantially all) of thepre-treated RMAC is sheared (such as into droplets) and forms apre-treated RMAC emulsion, such as through use of a batch Cowel's mixerand/or an in-line high shear mill.

In some embodiments, the emulsification process involves a dual-stepprocess. Specifically, for example, the emulsification solution (atabout 80-120° F.) can be placed in a high speed dispersion vessel thatis equipped with a mixer, such as a rotor-stator type blade type mixeror a Cowel's mixer. The pre-treated RMAC (at a temperature of about310-375° F.) is then added to the emulsification solution, and the mixeris used to pre-disperse the pre-treated RMAC throughout theemulsification solution. A first line fluidly connects the dispersionvessel to the input end of a colloid mill, and a second line fluidlyconnects the output end of the colloid mill to the dispersion vessel.The pre-treated RMAC/emulsification solution mixture is thusrecirculated from the dispersion vessel, through a line, through thecolloid mill, and back into the dispersion vessel. The positivedisplacement of the colloid mill serves to propel the mixture throughthis recirculation path. The mixer and the colloid mill can continue torun, and recirculation of the mixture can be continued, until thepre-treated RMAC emulsion has reached the desired consistency (e.g.,when the size of the pre-treated RMAC droplets in the emulsion are about2-20 microns in diameter, such as less than about 20 microns, less thanabout 18 microns, about 16 microns, about 14 microns, about 12 microns,about 10 microns, about 8 microns, about 6 microns, about 4 microns, oreven less than about 2 microns).

In another embodiment, a single step emulsification process may be usedwherein the pre-treated RMAC at a temperature of about 310-375° F. andthe emulsification solution at a temperature of about 80-120° F. areco-milled in a single pass through a colloid mill. One commerciallyavailable colloid mill useable for this process is the Dalworth MP-10,available from DALWORTH Machine Products (Fort Worth, Tex.). Anothercommercially available colloid mill useable for this process is theCharlotte G-75, available from Chemicolloid Laboratories, Inc. (GardenCity Park, N.Y.).

In another embodiment, the emulsification solution (such as at atemperature of about 80-120° F.) may be placed in a high speeddispersion vessel that is equipped with a mixer having a tip speed of atleast 5000 rpm (such as at least 6000 rpm, at least 7000 rpm, or even atleast 8000 rpm) (such as a Cowel's type mixer). The pre-treated RMAC(such as at a temperature of about 310-375° F.) is then added to theemulsification solution (such as via a fluid input line), and the mixeris used to pre-disperse the pre-treated RMAC throughout theemulsification solution. The pre-treated RMAC is high sheared at theblade tips of the rotating Cowel's mixer, providing the desireddispersion within the solution. The pre-treated RMAC feed is continueduntil the desired solid content is achieved. The combined componentswill continue to shear with the rotating mixer blade for an additionaltime to ensure that efficient particle distribution is achieved (e.g.,wherein the average size of the pre-treated RMAC droplets in theemulsion are about 2-20 microns in diameter, such as less than about 20microns, less than about 18 microns, about 16 microns, about 14 microns,about 12 microns, about 10 microns, about 8 microns, about 6 microns,about 4 microns, or even less than about 2 microns).

When contacted with a desired application site, the pre-treated RMACemulsion cures to form a cured coating or residue which can be used forany suitable purpose. In some embodiments, for example, the curedcoating is applied to any paved surface, such as any roadway, drivingsurface, and/or paved surface (such as to form a seal-coat and/orsurface sealer) in any suitable manner (such as by computer rate controlasphalt spreader truckers, hand spray wands, and/or by squeegees). Inother embodiments, the cured coating of the pre-treated RMAC emulsion isapplied to any industrial surface (such as to enhance corrosionresistance of steel, concrete, or the like, and/or to improve fireresistance of such surfaces), any building surface such as any roofsurface (such as to form a seal-coat and/or surface sealer for thesurface, such as proximate to any asphalt roof surface such as asphaltroof shingles), and/or the like, in any suitable manner. In this regard,the cured coating can form any suitable industrial coating composition,surface sealer composition, roof sealer composition, and/or roofingasphalt cement, or the like.

The cured coating can have any desired properties, such as high and/orenhanced resistance to water, fuel, and/or UV, as compared to curedcoatings prepared from RMACs that are not pre-treated. In one preferredembodiment, the cured coating comprises and/or exhibits no tackiness,low tackiness, and/or substantially no tackiness properties. In anotherpreferred embodiment, the cured coating comprises a softening point (asdetermined via ASTM D 36) greater than about 310° F., such as greaterthan about 320° F., about 330° F., about 340° F., about 350° F., about360° F., about 370° F., or even greater than about 380° F.—a point atwhich, for example, a weight (such as a steel ball having a diameter ofabout 9.5 mm and a mass of about 3.50±0.05 g) penetrates or settles atleast about 1 inch into a sample of the cured coating, using a ring andball softening point apparatus. Alternatively, or in addition, less than10 wt. % (such as less than about 9 wt. %, about 8 wt. %, about 7 wt. %,about 6 wt. %, about 5 wt. %, about 4 wt. %, about 3 wt. %, about 2 wt.%, about 1 wt. %, about 0.5 wt. %, or even less than about 0.1 wt. %)loss of the cured coating occurs, during the Wet Track Abrasion Test,when the cured coating is surface scrubbed after being submerged inwater for five days in accordance with International Slurry SurfacingAssociation (ISSA) TB-100, relative to the total weight of the curedcoating. Alternatively, or in addition, substantially no cured coatingsags and/or slips after exposure for about 2 hours at 212° F.±9° F. inaccordance with a Resistance to Heat Test in accordance with ASTM D2939.14. Alternatively, or in addition, substantially no blisteringand/or re-emulsification of the cured coating occurs after submersionfor greater than about 8 hours (such as about 12 hours, about 18 hours,about 1 day, about 2 days, or even greater than about 3 days) in waterhaving a temperature of about 75° F.±5° F., in accordance with aResistance to Water Test in accordance with ASTM D 2939.15.Alternatively, or in addition, less than about 10% (such as less thanabout 5% or less than about 1%) of the cured coating flows beyond aninitial reference line when subjected to the Wet Flow Test in accordancewith ASTM D 2939.19, such as when subjecting the cured coating for about30 minutes to a temperature of about 73.0° F.±4.0° F. and a relativehumidity of about 50±2%. Alternatively, or in addition, no continuedcombustion, slippage, and/or run-down of the cured coating occurs duringa Direct Flame Test in accordance with ASTM D 2939.20, such as when ablue flame (such as from a Bunsen burner) is applied for about 10seconds to a portion of a cured coating sample. Alternatively, or inaddition, minimal, low, and/or substantially no, and/or no cracking,chipping, surface distortion, color fading, lightening, and/or loss ofadhesion of the cured coating occurs when the cured coating is contactedwith and/or applied to a ceramic tile [such as a ceramic tile preparedin accordance with ASTM D 2939-25.1, such as an unglazed ceramic tilehaving a white, nonvitreous, dust-pressed body with an absorption rangeof 10-18%, determined in accordance with Test Methods C 67,approximately 150 mm by 150 mm by 9.5-14 mm (thickness)] and exposed toultraviolet light and condensation in accordance with the AcceleratedWeathering Test (as defined by ASTM G 154), such as for an exposureperiod of about 1000 hours that includes about 8 hours of exposure to UVlight (such as a UVA-340 lamp, 0-0.77 W/m2; v.1.0 calibration) at about50° C., and about 3.55 hours of exposure to condensation at 50° C.

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

It will be apparent to one of ordinary skill in the art that manychanges and modification can be made to the disclosures presented hereinwithout departing from the spirit or scope of the appended claims.

1. A method for preparing an asphalt cement emulsion, comprising: a)preparing a pre-treatment mixture comprising a rubber-modified asphaltcement; and b) contacting the pre-treatment mixture with water and clay.2. The method of claim 1, wherein the emulsion comprises less than 55wt. % of rubber-modified asphalt cement, relative to the total weight ofthe emulsion.
 3. The method of claim 1, wherein the clay is ahydrophobic clay.
 4. The method of claim 1, wherein the clay issepiolite clay.
 5. The method of claim 1, wherein the pre-treatmentmixture further comprises one or more emulsifiers.
 6. The method ofclaim 5, wherein one or more of the emulsifiers comprises a diaminecompound.
 7. The method of claim 5, wherein one or more of theemulsifiers comprise: i) about 30-50 wt. % of a compound comprising atleast two amine groups; ii) about 20-40 wt. % of an amine oxyalkylatecompound; iii) about 15-25 wt. % of a carboxylic acid compound; iv)about 5-10 wt. % of one or more aromatic hydrocarbon compounds; and v)about 5-10 wt. % of a tall oil compound.
 8. The method of claim 1,wherein the pre-treatment mixture is readily-emulsifiable.
 9. The methodof claim 1, wherein less than about 0.5 wt. % of the emulsion, relativeto the total weight of the emulsion, remains on a 850-um mesh sievefollowing contact of the sieve with the emulsion during the SieveEmulsion Test.
 10. The method of claim 1, wherein the emulsion iscurable to form a cured coating having a softening point of greater thanabout 350° F.
 11. The method of claim 10, wherein less than 5 wt. % lossof the cured coating occurs during the Wet Track Abrasion Test, relativeto the total weight of the cured coating.
 12. An asphalt cement emulsioncomprising: a) a pre-treatment mixture consisting of: i) arubber-modified asphalt cement; ii) one or more emulsifiers; and iii) anoptional anti-foam agent, polymer latex, sulfonic acid, and/or water;and b) water.
 13. The emulsion of claim 12, wherein the emulsioncomprises less than 55 wt. % of rubber-modified asphalt cement, relativeto the total weight of the emulsion.
 14. The emulsion of claim 12,wherein component (b) further comprises a clay.
 15. The emulsion ofclaim 12, wherein one or more of the emulsifiers comprise: i) about30-50 wt. % of a compound comprising at least two amine groups; ii)about 20-40 wt. % of an amine oxyalkylate compound; iii) about 15-25 wt.% of a carboxylic acid compound; iv) about 5-10 wt. % of one or morearomatic hydrocarbon compounds; and v) about 5-10 wt. % of a tall oilcompound.
 16. A method for coating an industrial surface, comprisingcontacting the surface with an asphalt cement emulsion comprising: a) arubber-modified asphalt cement; b) water; and c) a clay.
 17. The methodof claim 16, wherein the industrial surface is steel or concrete. 18.The method of claim 16, wherein the rubber-modified asphalt cement is arubber-modified asphalt cement that has been pre-treated with one ormore emulsifiers.
 19. The method of claim 18, wherein one or more of theemulsifiers comprise: i) about 30-50 wt. % of a compound comprising atleast two amine groups; ii) about 20-40 wt. % of an amine oxyalkylatecompound; iii) about 15-25 wt. % of a carboxylic acid compound; iv)about 5-10 wt. % of one or more aromatic hydrocarbon compounds; and v)about 5-10 wt. % of a tall oil compound.
 20. The method of claim 16,wherein the emulsion is curable to form a cured coating having asoftening point of greater than about 350° F.